CN router are different than US or EU routers. Different frequencies, slightly different hardware, etc... So NO. You may try and eventually brick your router. Do not install this firmware unless you are from China and have Chinese version of GT-AC5300.

I have a version for the Chinese market, but I am in Europe and use it. Asus acted like (the last goats), having programmatically limited the languages for other regions if the version is for the Chinese market. Now I have 3004384-45149 and I do not think that there is a difference for certain markets.
Ask, Asus.

I have a version for the Chinese market, but I am in Europe and use it. Asus acted like (the last goats), having programmatically limited the languages for other regions if the version is for the Chinese market. Now I have 3004384-45149 and I do not think that there is a difference for certain markets.
Ask, Asus.

There are differences between continents/countries. Big/small more or less. Every country in EU and outside have different WiFi bands allocations, also. Bands by the end of users allowed spectrum, and beyond. As for hardware I don't know, but I am sure there are differences also. Devices like smartphones, smart appliances don't see band from WiFi if you set some WiFi band that it is for another country. I have that situation in my home with router. I have basically everything connected to my WiFi. My GT-AC5300 is from Hungary which have different upper 5Ghz frequencies than my home appliances incl. smartphones. Some appliances don't see from channel 54 and above 5Ghz-1 and from 120 and above on 5Ghz-2.